电容电流过大造成的过电压讨论

The Discussion of Capacitive Current Results in Overvoltage in Power Distribution System

通过一起现场实际发生的变电站事故案例,对电容电流过大可能对故障相造成的危害进行讨论。案例中变电站10 kV母线是不接地系统,由于单相接地电容电流过大导致弧光过电压,对接地相产生了比不接地相更严重的绝缘损坏,最终击穿整段母线的接地相,造成更严重的负荷损失。根据这一现象提示,现场发生接地相绝缘损坏很有可能是电容电流过大造成。

This article aims to analyze an actual substation accident case.In this case,the 10 kV busbar of the substation is an ungrounded system.Due to the excessive current of the single-phase grounding capacitor,arc overvoltage is caused,which is more serious for the grounded phase than for the ungrounded phase.The insulation is damaged,and finally breaks down the ground phase of the entire busbar,causing more serious load loss.According to this phenomenon,it is suggested that the ground phase insulation damage occurred on site is likely to be caused by excessive capacitance current.